I’m not sure what type of primer it is. Its some type of high build primer in a spray can I purchased from KOI refinishing center.
Wow Kevin this is a great thread to follow! Please keep this going I can’t wait to see you finished.
For release I use Partall #2 and have used TR104 also, both of which work great. Your plug looks good enough that I would maybe only use wax and no PVA. But I’ll let others comment about the PVA use because that’s something that everyone has a diffent feeling about.
ughh… never use PVA…
Well the mold is made. I have yet to pop it off the plug though. I finished the layup yesterday morning. I’m planning on popping it off today after work. I ended up using 6 coats of Meguiars #8 only. I’m really hoping it pops easy.
it should do providing you didnt miss any area’s, tho unlikely tht you would have done after 6 coats,
I prepared the plug for laying up the mold. I attached some angle aluminum for flanges to add some stiffness to the mold. I then waxed the whole thing with 6 coats of Meguiars #8 Max Mold Release Wax.
IMG_5265.jpg by Kevin Sobkowiak, on Flickr
Then went w/o PVA and sprayed the gel coat on. Then a few layers of 0.75 oz mat, with some plain weave cloth draped over the corners at a 45 degree. Then 6 layers of 1.5 oz mat, and put some foam in there for added stiffness. Here it is all cured up with the green being the foam ribs.
IMG_5269.jpg by Kevin Sobkowiak, on Flickr
I removed the aluminum strips and they popped right off no problem. I was feeling pretty good about not using PVA at this point. Then shoved a bunch of wedges under and it started to pop quite nicely.
IMG_5272.jpg by Kevin Sobkowiak, on Flickr
Shortly after this point, I heard what I thought was the mold popping off the plug, but I was wrong. It was the plug breaking in half. The sunroof and hardboard sides had pulled off the plywood. I had the mold pulled off the plywood and the rest of it stuck inside my mold. Not good. I chipped the hardboard and bondo sides and was then left with just a sunroof at the bottom of the hole. At this point I was thinking about how screwed I was, and then decided to have a beer. Thankfully I widened the whole thing 1/8" and that gave me a small gap to grab onto the sunroof lip. I rigged up this prybar with some vice grips and a wedge. It popped off super easy.
IMG_5274.jpg by Kevin Sobkowiak, on Flickr
Disaster averted. I was sweating bullets. Looks like everything turned out nice besides tons of primer sticking.
IMG_5276.jpg by Kevin Sobkowiak, on Flickr
IMG_5277.jpg by Kevin Sobkowiak, on Flickr
So now here is my question, how do I remove all the primer w/o damaging the gel coat. The gel is a Fiberglast Orange Tooling Gel coat. The primer is this stuff.
IMG_5279.jpg by Kevin Sobkowiak, on Flickr
Mild success, after a big scare was the overall feel tonight.
Its simple. Pour some lacquer thinner on a rag, and just wipe it off. That is a very low quality primer. It will dissolve quickly in thinner. The lacquer thinner will not hurt your mold.
You can even brush the thinner on. It would be easier.
Do it this way…
Brush on the thinner until all of it is disolved.
wipe all the thinner off.
Brush on clean thinner or wipe it on.
Then wash the mold.
Then polish and wax it.
Test it on a small piece first. I don’t know what kind of gel coat you are using, but it should be fine. I always wipe my molds with thinner if they are dirty enough.
John
I agree ^, use thinner first, if thinner doesn’t work wet sand it with 1000grit until you remove it all and then buff. A small tip I’ve learned over time…I always use wax & pva between primer and gel coat when molding.
If thinner doesn’t work try acetone. That will dissolve any rattle can paint or primer but won’t hurt the mold.
I’ll give thinner a shot. I tested acetone on a bit of the gel coat overspray and it was breaking down the orange gel coat and coming off on the rag, so I figured that acetone wasn’t a good idea.
You should never use primer from a can on your plug. Only use Duratec for best results. Some primers are very porous and will stick.
Lesson learned for sure with that type of primer. I am using lacquer thinner and its taking the paint right off. Seems like it has no effect on the gel coat too. Perfect. Things are starting to look up!
Awesome! Glad to hear ifs working. I’ve never here of thinner eating fully cured gel coat. I’ve gotten craps stuck to the molds so many times in the past few years. I just set s rag with thinner and let it sit on the mold for thirty min or so. Every now and then ill check up on it and pour some fresh ruined on the rag to keep it saturated.
Show us the mold after its all cleaned up :).
Btw if you wanted to polish that mold up, it shouldn’t be difficult. Just wet sand it from 600 - 800 - 1000 - 1500 and buff / polish. If you have a nice smooth mold you should be able to start at a higher grit. 800 - 1000.
Post back soon :).
Ask and ye shall receive.
I cleaned the mold up with lacquer thinner. That got 95% of the paint off. There was some paint embedded into the gel, so I wet sanded with 1000 grit paper and it came right off. I do have one concern though. Seems as the wood grain texture transferred to the mold, even though I had it filled and sanded/primed. The wood grain texture is on a part of the mold that won’t be critical visually on the part. I am concerned about the vacuum bag sealing though. I’m not sure the bagging tape will be able to seal in those tiny nooks and crannies.
Here is the mold mostly cleaned up. I still need to get into the inside corner, but other than that its about all cleaned up.
IMG_5281.jpg by Kevin Sobkowiak, on Flickr
If you look closely at this pic, you can see the wood grain texture I’m talking about. I also did a polish test with some Meguiars M205 Ultra Finishing Compound I use on my cars. Polished it up pretty good even just by hand in that small spot.
IMG_5285.jpg by Kevin Sobkowiak, on Flickr
I believe sealing tape won’t have a problem with this surface, however if you need to make it flat get a flat sanding stick with 800grit and level it.
That surface is perfectly fine for sealing the tape, it won’t cause leaking issues.
If you’d like to get a smoother, “glass” like surface. Wet sand the mold with the following grits. 800 - 1000 - 1500 and then buff and polish. Works like a charm ;-).
I didn’t do much with the mold, but I got started on other equipment required for vacuum infusions. I need a vacuum pump, resin trap, and degassing chamber. For simplicity’s sake, I figured I’d mount them all on a platform so they’ll be packaged neatly. I’m not finished yet, but here is what I’ve got done.
The resin trap is 5" pipe, sch 10 stainless steel. I welded a 0.125" plate to the bottom and drilled some mounting holes. The degassing chamber is a 8" tube, 0.069" wall. These are just items I had around so I figured they were close enough to what I wanted so I went with it. I put some 1/4" NPT half couplings in them to hook them all together. Each chamber has a SS 1/4 turn valve. The resin trap has a 3.5" vacuum gauge to monitor the vacuum in my part during cure, and will be used to leak check the vac bag.
IMG_5298.jpg by Kevin Sobkowiak, on Flickr
IMG_5301.jpg by Kevin Sobkowiak, on Flickr
IMG_5303.jpg by Kevin Sobkowiak, on Flickr
I took my time welding to ensure I had no pinhole leaks.
IMG_5304.jpg by Kevin Sobkowiak, on Flickr
Angled upward for your viewing pleasure.
IMG_5305.jpg by Kevin Sobkowiak, on Flickr
You are an amazing welder! Good job :D.
Nice welding man.